The subject matter disclosed herein relates to the art of generators and, more particularly, to a generator rotor refurbishing system.
Generators typically include a stationary member or stator having a plurality of stator windings and a rotating member or rotor. The rotor includes a plurality of slots. Multiple conductors in the form of copper bars may be layered within each slot in the rotor. The copper bars are joined at corner regions through a brazing process to form a single multi-layered copper bar structure. Multiple multi-layered copper bar structures are joined together and nested one with another to form a “slinky-like” structure that defines a rotor coil. Each coil defines two or more field coil poles. Each field coil pole may include up to ten or more coils. As part of a generator repair process, the copper bars are removed, cleaned, and re-installed into the slots.
Removing the coils generally involves a team of support personnel and is initiated by cutting various ones of the copper bars of the multi-layered copper bar structure to separate one coil from another. Once cut and separated, the coil is removed as a single unit having a form that is similar to that of a loosely coiled spring. The coil, in its entirety is then moved to a cleaning area. In the cleaning area, operators employ a sand blasting process to remove varnish/epoxy and other surface fouling such as oxidation and the like. After cleaning, the team of support personnel re-installs the coil into the slots. The copper bars are then reconnected to re-establish a connection to the adjacent coil to re-form the multi-layer copper bar structure.